I stand corrected on the details, but still stand behind the basic idea that the 69 and 70 model heads are the only ones worth considering on a 289. In my honest opinion, for the $$$ invested, I'd rather own some after-market heads anyway. Iron GT40's would flow about the same and the price is hard to beat. I run Iron Windsor Jr.'s. I pocket ported them myself, and can't even compare the power to the stock heads. No dyno #'s, but it feels like 50 hp. Not bad for $700 (used w/ roller rockers)

BTW--I have better low end torque than before too.